85 



Localities: Harkness Slough, Willow Slough, Lily Lake, Long 

 Lake, Wood Slough. 



Vivijxira suhpiirpurea, Say. 



(Paludina siihpiirpurca. New Harmony Disseminator, ii, 245, 

 1829. ) 



Found only in Lily Lake, It is much like the preceding, but 

 has a slightly more tapering shell with the whorls flattened next 

 the revolving suture. 



Campeloma decisum, Say. 



{Limncea decisa, Say, Am. ed. Nich. Enc. 1,. 1817.) 



This was the largest and most abundant river snail observed. 

 It may be distinguished from the two preceding by its more 

 slender form, more tapering spire, and less convex whorls. The 

 general color is a uniform olive green, more or less stained towards 

 the apex with brown. Inside the aperture pure bluish white. An 

 example measures 1.37 inches in length, with the largest whorl .87 

 inch in diameter. The young are brought forth alive, and may be 

 found in the ovaries in the fall preceding the spring during 

 which they are set free. The adults go into the mud at the bot- 

 tom of the ponds and streams to hibernate. 



Localities: Harkness Slough, Quincy Bay, Willow Slough, Lily 

 Lake, Broad Lake, Wood Slough. 



Lioplax suhcarinata, Say. 



{Limncea suhcarinata, Say, Am. ed. Nich. Enc. 1, 1816.) 



Frequent in Willow Slough. Similar to the preceding, but 

 smaller and marked by an obtuse ridge extending along the mid- 

 dle of each whorl. One of the largest examples taken is just .50 

 inch in length. Like the other members of the family it is vivip- 

 arous. 



Family Kissoid^. 



Somafogyrus isogonus, Say. 



{Melania isogona, Say., New Harmony Disseminator, ii, 227, 

 1829.) 



Numerous examples from Willow Slough, Aug. 15. 



Amnicola limosa, Say. 



{Paludina limosa, Say., Jour. Acad. Nat. Sci. Phil., i, 125, 1817.) 

 Dredged in 3-5 feet of water. Willow Slough, Aug. 15. 



The clams are not very different from the river snails in their way 

 of living. They may be frequently seen in shallow water with 

 the front part of the body biiried in the mud and the soft white 

 "foot" thrust out of the shell. If watched intently under such 

 circumstances they may be observed to move slowly forward. 



